Revert #482: "aes: implement VAES AVX and AVX512 backends" (#496)

This reverts commit ad83428.

This implementation uses assembly, but the relevant intrinsics will be
stable in Rust 1.89, and we have a PR open to use them: #491

For a cleaner history, this reverts the assembly implementation so the
intrinsics-based implementation can be cleanly applied to an ASM-free
codebase, rather than as a replacement for the ASM.

Author: tarcieri

.github/workflows/aes.yml

@@ -16,7 +16,6 @@ defaults:
 env:
   CARGO_INCREMENTAL: 0
   RUSTFLAGS: "-Dwarnings"
-  SDE_FULL_VERSION: "9.53.0-2025-03-16"
 
 jobs:
   # Builds for no_std platforms
@@ -69,7 +68,7 @@ jobs:
     env:
       CARGO_INCREMENTAL: 0
       RUSTDOCFLAGS: "-C target-feature=+aes,+ssse3"
-      RUSTFLAGS: "-Dwarnings -C target-feature=+aes,+ssse3 --cfg aes_avx512_disable --cfg aes_avx256_disable"
+      RUSTFLAGS: "-Dwarnings -C target-feature=+aes,+ssse3"
     strategy:
       matrix:
         include:
@@ -98,80 +97,6 @@ jobs:
       - run: cargo test --target ${{ matrix.target }} --features hazmat
       - run: cargo test --target ${{ matrix.target }} --all-features
 
-  # Tests for the VAES AVX backend
-  vaes256:
-    runs-on: ubuntu-latest
-    env:
-      CARGO_INCREMENTAL: 0
-      RUSTFLAGS: "-Dwarnings --cfg aes_avx512_disable"
-    strategy:
-      matrix:
-        include:
-          - target: x86_64-unknown-linux-gnu
-            rust: 1.89.0-beta.2
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Intel SDE
-        run: |
-          curl -JLO "https://downloadmirror.intel.com/850782/sde-external-${{ env.SDE_FULL_VERSION }}-lin.tar.xz"
-          tar xvf sde-external-${{ env.SDE_FULL_VERSION }}-lin.tar.xz -C /opt
-          echo "/opt/sde-external-${{ env.SDE_FULL_VERSION }}-lin" >> $GITHUB_PATH
-      - uses: RustCrypto/actions/cargo-cache@master
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ matrix.rust }}
-          targets: ${{ matrix.target }}
-      # NOTE: Write a `.cargo/config.toml` to configure the target for VAES
-      # NOTE: We use intel-sde as the runner since not all GitHub CI hosts support AVX512
-      - name: write .cargo/config.toml
-        shell: bash
-        run: |
-          cd ../aes/..
-          mkdir -p .cargo
-          echo '[target.${{ matrix.target }}]'  > .cargo/config.toml
-          echo 'runner = "sde64 -future --"'   >> .cargo/config.toml
-      - run: ${{ matrix.deps }}
-      - run: cargo test --target ${{ matrix.target }}
-      - run: cargo test --target ${{ matrix.target }} --features hazmat
-      - run: cargo test --target ${{ matrix.target }} --all-features
-
-  # Tests for the VAES AVX512 backend
-  vaes512:
-    runs-on: ubuntu-latest
-    env:
-      CARGO_INCREMENTAL: 0
-    strategy:
-      matrix:
-        include:
-          - target: x86_64-unknown-linux-gnu
-            rust: 1.89.0-beta.2
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Intel SDE
-        run: |
-          curl -JLO "https://downloadmirror.intel.com/850782/sde-external-${{ env.SDE_FULL_VERSION }}-lin.tar.xz"
-          tar xvf sde-external-${{ env.SDE_FULL_VERSION }}-lin.tar.xz -C /opt
-          echo "/opt/sde-external-${{ env.SDE_FULL_VERSION }}-lin" >> $GITHUB_PATH
-      - uses: RustCrypto/actions/cargo-cache@master
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ matrix.rust }}
-          targets: ${{ matrix.target }}
-      # NOTE: Write a `.cargo/config.toml` to configure the target for VAES
-      # NOTE: We use intel-sde as the runner since not all GitHub CI hosts support AVX512
-      - name: write .cargo/config.toml
-        shell: bash
-        run: |
-          cd ../aes/..
-          mkdir -p .cargo
-          echo '[target.${{ matrix.target }}]'  > .cargo/config.toml
-          echo 'runner = "sde64 -future --"'   >> .cargo/config.toml
-      - run: ${{ matrix.deps }}
-      - run: cargo test --target ${{ matrix.target }}
-      - run: cargo test --target ${{ matrix.target }} --features hazmat
-      - run: cargo test --target ${{ matrix.target }} --all-features
-
-
   # Tests for CPU feature autodetection with fallback to portable software implementation
   autodetect:
     runs-on: ubuntu-latest

aes/Cargo.toml

@@ -31,7 +31,7 @@ hazmat = [] # Expose cryptographically hazardous APIs
 
 [lints.rust.unexpected_cfgs]
 level = "warn"
-check-cfg = ["cfg(aes_compact)", "cfg(aes_force_soft)", "cfg(aes_avx256_disable)", "cfg(aes_avx512_disable)"]
+check-cfg = ["cfg(aes_compact)", "cfg(aes_force_soft)"]
 
 [package.metadata.docs.rs]
 all-features = true

aes/src/armv8.rs

@@ -25,13 +25,6 @@ use cipher::{
 };
 use core::fmt;
 
-pub(crate) mod features {
-    cpufeatures::new!(features_aes, "aes");
-    pub(crate) mod aes {
-        pub use super::features_aes::*;
-    }
-}
-
 impl_backends!(
     enc_name = Aes128BackEnc,
     dec_name = Aes128BackDec,
@@ -93,6 +86,18 @@ macro_rules! define_aes_impl {
             decrypt: $name_back_dec,
         }
 
+        impl $name {
+            #[inline(always)]
+            pub(crate) fn get_enc_backend(&self) -> &$name_back_enc {
+                &self.encrypt
+            }
+
+            #[inline(always)]
+            pub(crate) fn get_dec_backend(&self) -> &$name_back_dec {
+                &self.decrypt
+            }
+        }
+
         impl KeySizeUser for $name {
             type KeySize = $key_size;
         }
@@ -177,6 +182,13 @@ macro_rules! define_aes_impl {
             backend: $name_back_enc,
         }
 
+        impl $name_enc {
+            #[inline(always)]
+            pub(crate) fn get_enc_backend(&self) -> &$name_back_enc {
+                &self.backend
+            }
+        }
+
         impl KeySizeUser for $name_enc {
             type KeySize = $key_size;
         }
@@ -236,6 +248,13 @@ macro_rules! define_aes_impl {
             backend: $name_back_dec,
         }
 
+        impl $name_dec {
+            #[inline(always)]
+            pub(crate) fn get_dec_backend(&self) -> &$name_back_dec {
+                &self.backend
+            }
+        }
+
         impl KeySizeUser for $name_dec {
             type KeySize = $key_size;
         }